<template>
  <!-- 筛选区 -->
  <div class="sub-filter" v-if="filterData && !filterLoading">
    <div class="item">
      <div class="head">品牌：</div>
      <div class="body">
        <a href="javascript:;" :class="{ 'active': item.id === filterData.brands.selectedBrand}"
           v-for="item in filterData.brands" :key="item.id"
           @click="changeBrand(item.id)">{{ item.name }}</a>
      </div>
    </div>
    <div class="item" v-for="item in filterData.saleProperties" :key="item.id">
      <div class="head">{{ item.name }}:</div>
      <div class="body">
        <a href="javascript:;" :class="{ 'active': prop.id === item.selectedAttr }" v-for="prop in item.properties"
           :key="prop.id" @click="changeProp(item, prop.id)">{{ prop.name }}</a>
      </div>
    </div>
  </div>
  <!--   加上骨架效果 -->
  <div v-else class="sub-filter">
    <XtxSkeleton class="item" width="800px" height="40px"/>
    <XtxSkeleton class="item" width="800px" height="40px"/>
    <XtxSkeleton class="item" width="600px" height="40px"/>
    <XtxSkeleton class="item" width="600px" height="40px"/>
    <XtxSkeleton class="item" width="600px" height="40px"/>
  </div>
</template>
<script>
import { ref, watch } from 'vue'
import { useRoute } from 'vue-router'
import { findSubCategoryFilter } from '@/api/category'

export default {
  name: 'SubFilter',
  setup (props, { emit }) {
    const route = useRoute()
    //  监听二级类目ID的变化获取筛选数据
    const filterData = ref(null)
    const filterLoading = ref(false)
    watch(() => route.params.id, (newVal) => {
      // 变化后的Id有值且处在二级类名路由下
      if (newVal && `/category/sub/${newVal}` === route.path) {
        //  发送请求获取数据
        findSubCategoryFilter(route.params.id).then(data => {
          filterLoading.value = true
          // 每组可选的筛选条件缺失，处理下数据加上全部
          // 给每组数据加上一个选中的ID
          // 1.品牌
          data.result.brands.selectedBrand = null
          data.result.brands.unshift({
            id: null,
            name: '全部'
          })
          // 2.属性
          data.result.saleProperties.forEach((item) => {
            item.selectedAttr = null
            item.properties.unshift({
              id: null,
              name: '全部'
            })
          })
          //  设置修改的数据
          filterData.value = data.result
          filterLoading.value = false
        })
      }
    }, {
      immediate: true
    })
    // 获取筛选参数的函数
    const getFileterParams = () => {
      const obj = {
        brandId: null,
        attrs: []
      }
      // 品牌
      obj.brandId = filterData.value.selectedBrand
      // 销售属性
      filterData.value.saleProperties.forEach(item => {
        if (item.selectedProp) {
          const prop = item.properties.find(prop => prop.id === item.selectedProp)
          obj.attrs.push({
            groupName: item.name,
            propertyName: prop.name
          })
        }
      })
      if (obj.attrs.length === 0) obj.attrs = null
      // 参考数据： {brandId: '', attrs: [{groupName: '', propertyName: ''}, ...]}
      return obj
    }
    // 记录当前选择的品牌
    const changeBrand = (brandId) => {
      // 已选择自己后再次点击自己，直接返回
      if (filterData.value.selectedBrand === brandId) return
      filterData.value.selectedBrand = brandId
      emit('filter-change', getFileterParams())
    }
    // 记录当前选择的销售属性
    const changeProp = (item, propId) => {
      // 已选择自己后再次点击自己，直接返回
      if (item.selectedProp === propId) return
      item.selectedProp = propId
      emit('filter-change', getFileterParams())
    }
    return {
      filterData,
      filterLoading,
      changeBrand,
      changeProp
    }
  }
}
</script>
<style scoped lang='less'>
// 筛选区
.sub-filter {
  background: #fff;
  padding: 25px;

  .item {
    display: flex;
    line-height: 40px;

    .head {
      width: 80px;
      color: #999;
    }

    .body {
      flex: 1;

      a {
        margin-right: 36px;
        transition: all .3s;
        display: inline-block;

        &.active,
        &:hover {
          color: @xtxColor;
        }
      }
    }

    .xtx-skeleton {
      padding: 10px 0;
    }
  }
}
</style>
